The use of solid sorbents for use in pollution control has, in many cases, been rejected in favor of liquid sorbtion systems. One of the reasons for rejection of solid sorbents is their low sorption capacity as compared to other systems, and their limited life (loss of capacity due to use).
Clinoptilolite is a natural zeolite found in substantial deposits in the western United States and elsewhere. Its sorption properties for SO.sub.2 and other gases have been measured and reported in the literature, for example by J. K. Tamboli and L. B. Sand in "Procedings of the Second International Clean Air Congress", pp. 861-864, published by Academic Press, New York, 1971. In that article the authors show that natural clinoptilolite, acid treated, has about 75% of the static capacity for SO.sub.2, at a partial pressure of one-half atmosphere, as does synthetic mordenite. The article concludes that natural siliceous zeolites such as clinoptilolite may have application in pollution control, particularly where acid stability is required. R. M. Barrer and M. B. Makki in Canadian Journal of Chemistry, Vol. 42 (1964) pp. 1481 to 1487, report on the sorptive properties of acid treated natural clinoptilolite for nitrogen, water, and various organic compounds. So far as applicant is aware, no commercial application of clinoptilolite in the sorption of acid gases has been made to date.